In typical network broadcasting, about eight minutes of advertisements are included in a thirty-minute program, representing a ratio of content to advertisements of about 3 to 1. In addition, each advertisement break in a full-length program lasts at most 90 seconds, usually between 30 seconds to 60 seconds. For online content viewing, however, it has been found that viewers tend to tolerate longer advertisement breaks. Online viewing patterns are also different than broadcast viewing patterns. For example, online users can instantly jump to a new program section during playback, while users of even Digital Video Recorders (DVR) require more time to skip to a different section of a program.
In general, it is advantageous to maximize advertising time in a program because it enhances values to advertisers and increases revenue to broadcasters. To measure the value of advertisements, the Nielson's rating system provides the C3 ratings, which is a metric that rates average commercial minutes in live broadcast programming plus three days of online playback of the program after live broadcasting. To comply with the C3 rating system, a program provider can encode Nielsen audio watermarks in each program file formatted for online viewing.